Winding core



FIG. 1 is a 3-dimensional view of a winding core, showing our new design;

FIG. 2 is a front elevation view (rear is the same) thereof;

FIG. 3 is a side elevation view (opposite side is the same) thereof;

FIG. 4 is a top plan view thereof; and,

FIG. 5 is a bottom plan view thereof.

The broken lines shown in the drawings depicts portions of the winding core that form no part of the claimed design. 

CLAIM The ornamental design for a winding core, as shown and described. 